1. Field of the Invention
The present invention relates to fluorescent lamps, and more particularly to an electronic ballast circuit which includes means to regulate load voltage by varying or pre-programming the input voltage and frequency to power fluorescent lamps.
2. Background Art
A background art search directed to the subject matter of this application and conducted in the United States Patent and Trademark Office disclosed the following U.S. Pat. Nos.: 4,071,812 4,926,097 5,049,788 4,730,242 4,935,857 5,055,746 4,851,739 4,999,546 5,144,205 4,860,184 5,043,680 5,191,263 4,920,302
None of the patents uncovered in the search discloses means for varying the input voltage or frequency, or a combination of both, to regulate the output load voltage dynamically to achieve a dimming operation of lamps, or in the alternative to have a regulated steady state load and no load voltage by programming the frequency and input voltage in the load resonant circuitry.
Virtually all of the circuits provided in the background art seem to be of the single ended type, providing circuitry used with a single or a known load.